VITAL AC/DC Flashcards
(14 cards)
What is the basis for battery capacity?
INOPERABLE < 105V, powers essential EFW loads for 2 hours and 3 cycles of ES breakers (close and trip).
When are vital buses declared INOPERABLE?
If powered from TRA/TRB.
What powers the 1A inverter normally and during loss of AC?
Normally powered by 1A ES MCC; powered by DC during loss of AC.
What does ATA feed?
ICS and NNI AUTO power.
What does ATB feed?
ICS Hand, PPC, and Mark V.
What are the float and equalize voltages for battery charging?
Float = 130V, Equalize = 135V.
What are the 8-hour and 2-hour discharge rates for the battery?
8-hour rate = 177.5A/hr, 2-hour rate = 475A/hr (non-linear response).
What conditions must be met for a battery to be considered OPERABLE?
(1) Connected to DC train, (2) Voltage 129-131V on float or 134-136V on equalize, (3) Cell voltage >2.07V, (4) Float current <2 Amps.
What precaution should be taken when restoring a battery charger?
Close the DC breaker first to prevent damage.
Why should the battery room be ventilated during equalize charging?
To prevent hydrogen gas buildup.
What does a ground detector reading of 0 indicate?
Ground on PN or N.
What does a ground detector reading of INFINITE indicate?
No ground on PN or N.
If battery life is projected at 3.5 hours at 300 Amps, how much time is gained by reducing the load to 150 Amps?
Battery life increases to >7 hours (non-linear relationship).
What supplies the 1A inverter during loss of 1A ES MCC?
125VDC via the 1A Distribution Panel.
